As is known, sensing elements are used in a variety of applications to sense characteristics of an environment. Sensing elements include, but are not limited to, pressure sensing elements, temperature sensing elements, light sensing elements, acoustic sensing elements, and magnetic field sensing elements.
Magnetic field sensing elements can be used in a variety of applications. In one application, a magnetic field sensor can be used to detect a direction of a magnetic field. In another application, a magnetic field sensing element can be used to sense an electrical current. One type of current sensor uses a Hall effect magnetic field sensing element in proximity to a current-carrying conductor.
Planar Hall elements and vertical Hall elements are known types of magnetic field sensing elements that can be used in magnetic field sensors. A planar Hall element tends to be responsive to magnetic field perpendicular to a surface of a substrate on which the planar Hall element is formed. A vertical Hall element tends to be responsive to magnetic field parallel to a surface of a substrate on which the vertical Hall element is formed.
Other types of magnetic field sensing elements are known. For example, a so-called “circular vertical Hall” (CVH) sensing element, which includes a plurality of vertical magnetic field sensing elements, is known and described in PCT Patent Application No. PCT/EP2008056517, entitled “Magnetic Field Sensor for Measuring Direction of a Magnetic Field in a Plane,” filed May 28, 2008, and published in the English language as PCT Publication No. WO 2008/145662, which application and publication thereof are incorporated by reference herein in their entirety. The CVH sensing element is a circular arrangement of vertical Hall elements arranged over a common circular implant region in a substrate. The CVH sensing element can be used to sense a direction (and optionally a strength) of a magnetic field in a plane of the substrate.
Output signals from the vertical Hall elements of a CVH sensing element are typically generated sequentially, resulting in a substantial time necessary to generate all of the output signals from the CVH sensing element.
Various parameters characterize the performance of sensing elements (and sensors that use magnetic field sensing elements) in general, and magnetic field sensing elements (and sensors) in particular. Taking a magnetic field sensing element as an example, these parameters include sensitivity, which is a change in an output signal of a magnetic field sensing element in response to a change of magnetic field experienced by the magnetic sensing element, and linearity, which is a degree to which the output signal of the magnetic field sensing element varies in direct proportion to the magnetic field. These parameters also include an offset, which is characterized by an output signal from the magnetic field sensing element not representative of a zero magnetic field when the magnetic field sensing element experiences a zero magnetic field. Other types sensing elements can also have an offset of a respective output signal that is not representative of a zero sensed characteristic when the sensing element experiences the zero sensed characteristic.
It would be desirable to provide circuits that can process sensor output signals from a plurality of sensors to provide a processed output signal having improved characteristics, including, but not limited to, an improved offset.
It would also be desirable to provide a CVH sensing element arrangement for which the output signals from the CVH sensing element are generated more quickly.